Local-anesthetic syringe



Aug. 21, 1928.

Filed June 7, 1927 m@ 3R., ma w w w. W. hm,

Patented Aug..y Z1, 1928.

GEORGE P. rrrKiN, or EERGENEIEED, NEW JERSEY., y

LOCAL-ANSTl-IETIC SYRINGE.

Appiicaaoii inea June 7, 1927. serial No. 197,042.

This invention relates to medical and surn gical apparatus and has particular reference todevices for administering a local anaesthetic.

Among the objects of the `invention iste provide improved means for obviatingthe necessityV for frequent withdrawal and reinsertion of the hypoderinic needle for the purpose'of administering a larger quantity of luid than the barrel of the syringe is calculated to hold.

A further object of the invention is to provide what is in the nature of` a Vforce pump, of which the Syringe mechanism'is a pai-aand which is peculiarly adapted foi reliability and dependability while the init portant function of'admnistering,the anaesthetie is taking place.

A still further object-of the invention is to include an attachment, for the syringe that will enable practically the last drop of the fluid kto be withdrawn Afrom the receptacle and inject it into the tissues.

With the foregoing and other objectsinV View the invention consists in the arrangement and combination of parts hereinafter described and claimed, and while the inven-A tion is not restricted to the exact details of construction disclosed and suggested herein;

still for the purpose of illustrating a practical embodiment thereof reference is had to the accompanying drawings in which like reference characters designate the saine ,parts in the several views, and inl which.-

Figure 1 is a side elevation of a preferred embodiment of the invention, partsbeing in section. I

Fig. 2 is a vertical transverse section on `the line 2-2 of Fig. 1 and showing apredrawingsl show my improved syringe` as comprising a barrel lO'preferably cylindrical n Ml in form and of any suitable material, preferably of glass or some other transparent material foi' the betteir observationvof'the treatment while it is beingpeiforined. The barrel 10 is formed with a head 11 at one endn havin@ a )ort 12 extending therethrough and b l i.: i

havinga nipple extension 18. for the attachment by any suitable means as at 141 of a needle 15, the needle having a port as usual communicating with the port 12. As the ybarrel head.

barrel-1Q is construetedthe end opposite the head l1 is openbut provided with an exten nal flange 16 against which a collar 17'f'ab`uts and is held by 'meansof a head 18 having a thread communicating withl an `internal thread at the outer end of the collar as shown at'19. The head 18,bearing against the end of the barrel 10, reacts to hold the collar 17 firmly against the liange 16, either directly or through the intermediary of a gasket 20, making a firm Huid tight connection between the head 18 and the barrel, andl affording also means for holding or manipulating vthe barrel as through the finger pieces .21 attached to the collar.

vFittedslidably within thesniooth interior surface of the barrel isapiston 22 having formedV therein `an interior cavityv or socket V23, the outer endof which is internally screw threaded while the .inner end communicates through a port 24 with the yport 12vat the The socket 28 constitutes"y a valve chamber within which. is fitted loosely a valve 25 having a stem26 fitted slidably rin the port 27 of a piston rod 28,'the forward i end of which at 29 is threaded into the threaded end of the socket. The valve is adapted to reciprocate toward and fiom1the valve; seat 30, the degree of reciprocation being limited by means ofsuitablelprojections between the Valve and the bodyof the piston, shown herein as a plurality of pins 31 fixed to the valve and adapted to iinpinge against the piston on opposite sides of the port 24. i f

r The remote portion ofthe piston rod is fit-ted kfor reciprocationfinthe head1?)ofthe barrelA and carries outside of said head a valve body 82 and adjacent to whichgis a `thumb piece 33 all vrigidly connected to- 84 indicates a nipple threaded into gether. a bossf35 projectinglaterauy frein the body 32 and Whose inner end at 3G yconstitutes a seat for a valve 37 within the` body. This valvehas a stem 38 fitted looselyxin the port:

89 of the nipple, and the valve'isadapted to 4reciprocate between saidseatBG when'elosed anda plurality of projections 31 formed on orcarriedby the body, when open. Thenipplejl is detachable from the body 32 for f the valve on reverse pressure, irrespective of y the position in which ythe apparatus may be used or held at any time. Syringes as heretoiore made and on the market so far as my experience justifies my opinion, are such that they must be held in a certain position toV And this'too without demanding the use ofA any springs or other mechanical means for insuring the seating of the valve.L Y

Connected to the rnipple 34 is a flexibl tube 4c@ :of 'any suitable material or length and adapted to be projected Vinto a recep-A tacle el from which the anaesthetic is sup-k plied. yThe lower'vor inner end of the tube i0 is fitted with a metal foot .42 having' a central bore 43 -communicating with the tube and having'a flat bottom surface with oner or more transverse scores 44 communicating at ktheir inner ends with the bore l The form of the foot 42 insures` that the flat bottom surface thereof Awill rest uponthe bottom of the receptacle and because ofthe scores lll the last drop or vestige of the-fluid in the receptacle may be withdrawn therefrom.

From the foregoing specific description of the mechanism, its mode of operation may be brieiiy summarized as follows: With the receptacle 41 supplied with the 'properv ansthetic'to be injected into the tissues and with the foot 42 inserted into vthe receptacle,

the operator grasping the instrument with his first two lingers in the loops or finger pieces 21 and his thumb in the thumb piece 33, will have complete control of theinstrunient for the insert-ion of theneedlc lo asv required and he willbe enabled to reciproF` cate the piston 22 by action `of yhis thumb. The outward or rearward movement of the piston, or away from the head l1, wiilset up a vacuum between the piston and the headll, the tissues serving normally to olistruct the passage way through the needle unless the pointed needle should inadvert ently be locat-ed'in a blood `vessel at which time the entrance of the blood into the transparent barrel will apprise the operator of this fact and he will reset the needle kso as to avoid vobj ection. As result of the vacuum above mentioned, the fluidifrom the receptacle williow through the tube and hollow piston rodpastthe valves 3T and 25 and lill the space between .the piston and the head ll. On the forward reciprocation yof the pistomthe valves will close directly and j cause the ejection of the fluid from the barrel through the needle into the tissues. I

' have found that for the sake of the highest ydegree `of efficiency and vleastloss of effec tiveness due to slipping of the Huid, two

valves arranged in tandem ory in alignmentv with each other areof peculiar advantage. There `is always a possibility that for some reasonor other one valve may fail tofseat fully and completely, `and if there is a lea-l(- age through [the valveat the time when the injecting stroke is ybeing made, the instrument fails seriously. Vto perform'its proper function.

1 I'claim: f L

l. Theherein described anaesthetic syringe comprising fa barrel having va needle connection at one end, a. piston slidable witliinthe barrel'. said piston having a sockket withinit, a tubular rod connected Lto the piston, the endof the frodi adjaceiitwto the pistonil constituting arly-,valve seat, a. valve seated loosely within the piston socket and adapted to sea-t against said seat, means to reciprocate the piston and rod tofcause f fluid to pass through kthe rod and piston'past the valve, anabutment pin being provided to prevent the valve from'seatinglclosely against the piston remote Vfrom said seat,

andmeans to convey fluid' from a receptacle to said piston rod.' Y f V2. In an anaesthetic' syringe, a barrel of transparent'- niaterial having at one end an integralfhead with 'a'fport therethrough, needle `connections v. communicating with said port,.the other end of the barrel vbeing open, ahead for closing the open end of` theY barrel, 'a piston slidableI in` the barrel, a ypistonl rod extending through the second mentioned head, means to convey i'iuid into the barrel for filling it on` reciprocation of the pistoi1,valve.means to control t-he reverse moven'ient `ot' the fluid and cause the ejection thereof from the barrel through the needle mechanism, saidvvalve mechanism comprising a ivalve of light Vvmetal and n rigid yabutment Hpin. imeans (zo-operating` f' therewith to' insure a fluid space betweenL the valve and thevalvebody yremote from the Seat, j v. y y

y Intestimony-whereof I afliX my signature. GEORGE P. 'IITKIN 

